Valve-gearing



(No Model.) 2 Sheets-Sheet l.

R. G. V. MYTTON.

' .VALVB GEAR-ING.

No. 427,704. Patented May 13-, 1890.

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1 Q WITNESSES I 7 I INVENTOR\ ib ll- //////4 (No Model,) 2 Sheets-Sheet2.

R. G. v. MYTTON; VALVE GEARING.

No. 427,704. Patented May 15 1890.

|!i Q2 LL m m 2 O 7 o fi s i k, v l I a H Q K q 0 r O o w j WITNESSES WQ V 4 W UNITED STATES PATENT OFFICE.

RICHARD GRIFFITH VERE MYTTON, OF BIRMINGHAM, ALABAMA.

VALVE-GEARING.

SPECIFICATION forming part of Letters Patent No. 427,704, dated May 13,1890.

Application filed December 5, 1889 Serial No. 332,678. (No model.)

To all whom it may concern.-

Be it known that I, RICHARD GRIFFITH VERE MYTTON, a citizen of theUnited States, residing at Birmingharmin the county of Jefferson andState of Alabama, have invented certain new and useful Improvements inValve-Gearing; and I do declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same, referencebeing had to the accompanying drawings, and to the letters of referencemarked thereon, which form a part of this specification.

My invention relates to that class of valve gears in which the valvesare operated by means of a rocking disk pivoted to a driving orintermediate shaft and capable of being canted thereon by means of ashifter placed on or adjoining the said shaft.

The obj ects of the improvement are, first, to obtain lead, where suchis required, without the additionof extra parts; second, to provideaconstruction in which all the parts will cooperate in gainingsimplicity by arranging certain parts to perform double duty, or,rather, serve two purposes; third, to provide for wear where such ismost liable to take place; fourth, to provide a simple, practical, andefficient means of moving the shifter in altering the travel of valveand reversing it; fifth, to provide a simple and practical c011-struction which will facilitate its application to a locomotive byenabling certain parts now in general use on locomotives to be retained,and thus avoid the necessity of remodeling nearly the complete machine,and, sixth, to provide a new and improved means of compensating for thevertical movement of the locomotive in its axle-boxes, so that no matterhow violently the engine may be pitching the valves will moveasaccurately as they would if the engine were perfectly steady. l attainthese objects bymeans of the mechanism set forth in the accompanyingdrawings, where 111= Figure 1 is an end elevation, partly in section, ofmy improved valve-gear, the section being taken on line 00 m, Fig. 2.Fig. 2 is a plan partly in section. Fig. 3 is an edge elevation of thesector. Fig.4 is a side and edge Fig. 8 is a plan and elevation of thehorizontal rock-shaft and arms.

The same letters refer to the same parts in all the figures.

The shaft A may be either the main driving-axle of the locomotive orotherengine or a counter-shaft geared thereto. Fit-ted on the shaft andkeyed thereto is a sleeve B, having pins b, which form the pivots forthe rocking disks, projecting one on each side at diametrically-oppositepoints. Midway between the two pins a longitudinal slot 1) is cutcompletely through one side of the sleeve, extending from one end of thesleeve nearly to the other. At the open end of the slot a bridge 6integral with or attached to the sleeve, crosses the slot, the inneredge of the slot forming with the bridge a way or guide in which slidesthe arm 0 of the shifter G. This latter consists of a sleeve or collarprovided with flanges c and sliding freely on the shaft A. In alocomotive-engine the shifter is supplied with two arms 0, projecting inopposite directions along the shaft or axle, one being v ninety degreesin advance of the other around the axle, and each arm operating to canta disk.

The rocking disk or disks D are formed in halves diametrically an dtongued and grooved one into the other, as shown in Fig. 5,'the twoparts being held together by means of two eyescrews (Z, screwed into onepart and keyed to the other, as shown. One of these screws forms awrist-pin, by means of which the disk is connected with the shifter O,the meeting edges of the halves of the disk being cutaway at that pointto permit the arm a of the shifter to pass through. Said arm is providedwith two outwardly-projecting jaws 0 between which is received thewrist-pin d. The disk being pivotedly mounted on the pins Z), it isplain that .any movement of the shifter along the shaft A will cant thedisk one way or the other from an equatorial posi- It is also evidentthat the tion on the shaft.

wrist-pin d must be parallel with the pivotpins Z) in order to preventit from binding in the jaws of the shifting-arm. In all cases the pivotsb are set at right angles to the shaft, and in the case of a locomotivethose on one sleeve are set ninety degrees ahead of those on the other.The opening through the disk is made elliptical, with its major axis atright angles to the axis of the pivots, in order to allow room for thedisk to rock on the shaft. I obtain any-desired lead of the valve byplacing the disk on the shaft at an angle with the axis of the pivots b,the holes for the pivots being made obliquely to the plane of the disk,as shown in Fig. 2. The proper angle to give the desired lead havingbeen once determined and the disk accurately set, there is novalve-settin g to be done.

To convey the rocking motion of the disk to the valve, the periphery ofthe disk is grooved and a strap E is placed therein provided withdiametrically-opposite journals e, on which are pivoted the arms of thestirrup F. Midway between the pivotal points of the arms the stirrup hasa stem or shaftf projecting at right angles with the shaft A and adaptedto be received in a suitable bearing, whereby the stirrup is supportedin proper relation to the shaft. The oscillating or rocking motionimparted to this shaft f is readily caused to reciprocate the valve-stemby means of a rock-arm F and wrist-pin f.

In a locomotive, since the stem f must be supported on the frame, whilethe axle A is carried in the axleboxes, it is necessary to provide meansfor permitting the axle to rise and fall in the pedestals withoutdisturbing the action of the gear. means of the devices shown in Fig. 4,where the sides of the strap adjacent to the journals are faced off andthe stirrup-arms are slotted to permit the journals to rise and falltherein, the journals having large heads 6', or some similar device, tohold the stirrup in place. The strap here shown is made in two parts, soas to be adjustable to the disk and to provide for taking up wear. Thetwo parts of the strap are held together at one end by a bolt e and atthe other end by a wedge 6 driven between opposing lugs on the twoparts.

The mechanism for moving the shifter to and fro along the shaft andholdingit and the disk or disks at any desired point is as follows:Fulcrumed upon a fixed brace G, which in a locomotive may be fastenedacross between the frames, is a lever H, capable of turning horizontallyabout a vertical pivot G, and having at one end a fork H to connect itwith the shifter, as hereinafter more fully described, and at the othera fork H the arms of the forks lying in vertical planes.

.In the fork H is pivoted a small block I, whose top, bottom, front, andback may be perpendicular; but whose sides are chamfered off orinclined, so that a section of the block forms a rhomb, as shown in Fig.3. The block This I accomplish by is thus fitted to slide between theflanges of a peripherally grooved sector K, secured obliquely on atumblingshaft L. To compensate for the versed sine of the angle, throughwhich the arm of the lever moves and which would tend to draw the blockI out of the grooved sector, the curve of the sector is struck with aradius greater than the distance from the center of the tumbling-shaftto the edge of the sector, so that the block has a solid bearing inwhatever position the sector may be. It is obvious that with certainproportions of the sector and the lever arm, through which the shifteris moved, the curves of the sector will become a straight line, and ifthe arms of the lever be very small the curve may have to be describedwith a convex instead of a concave surface.

In a locomotive the tumbling-shaft L may be the one now used to shiftthe links, the lifting-arms being dispensed with. The shaft may berocked, as usual, by the arm L and the reach-rod H. WVhen the shaft isrotated from one position to anothpr, the inclined sector acts to throwthe lever II one way or the other and thereby slide the shifter alongthe main shaft A, whereby the disks D are more or less inclined, and thetravel of the valve is regulated. In moving from one extreme of itstravel to the other the sector causes the disks to be canted from oneposition to the opposite, and thereby operates to reverse the enginefrom full front to full back, or vice versa. 7 hen the sector isarrested at any intermediate position, itholds the disks at such anangle that the steam is cut off more or less early in the stroke. At thesame time the lever H and shifter O are rigidly locked againstdisplacement by the strain on the disks. The lever is conected to theshifter, preferably by the following means: An elliptical ring N isplaced in the groove of the shifter and accurately fitted between theflanges c. The ring may be made in halves and bolted together, or one ofthe flanges c on the shifter may be made removable, to allow the ring tobe slipped on. As shown in Fig. 1, the minor axis of the ring is placedvertically, the major axis providing for the necessary play equal to theversed sine of the angle described by the end of the lever H in movingthe shift-er. The axial pins n are placed on the line of the major axis,and have an accurate sliding lit in holes in the arm of the fork H, thespread of the fork and the length of the pins being great enough toprovide for the verticalplay of the shaft A in its bearings. Thisvertical play may be provided for by placing the major axis of the IIOmode of doing this is shown, the first illustratin g the arrangementemployed when the disks are near the ends of the axle, and the other,that to be preferred when the disks are for some reason obliged to beclose together. A transverse brace O is bolted securely to the frame P,having offsets 0, in which are journaled the stirrup-shafts f.Horizontal rocker-arms Q are suitably mounted on the frames transverselythereto, and their inner ends are connected by rods R with the wristpinf of the stirrups. The rods are provided with some accurate device foradjusting their lengths, such as turn-buckles 0'. The outer ends of therocker-arms Q are connected with the valve-stems S.

I am aware that so-called drunken disks have been used in valve-gearing,and I do not claim, broadly, such a disk as the actuating element of avalve motion; but

\Vhat I do claim, and desire to secure by Letters Patent, is{

1. In a valve-gearing, the disk D, formed in halves, tongued and groovedtogether, and united by eyebolts d, the meeting edges of the parts beingcut away adjacent to one of said bolts, whereby it is adapted to serveas a wrist-pin for moving the disk, substantially as described.

2. The combination, with the shaft A and pivoted disk D, of the shifterG, consisting of a flanged sleeve encircling the shaft, and having anarm engaging with the disk, and an elliptical ring N, fitted between theflanges of the shifter, and provided with pins 0?, sub stantially asdescribed.

3. The combination, with the shaft A, of the sleeve 13, secured thereto,having the pins 1), the slot b, and bridge Z1 the shifter C, sliding onthe shaft and having an arm 0, fitted to slide in the slot Z), the diskD, pivoted on the pins Z), and having a wrist-pin d, engaged by the armof the shifter, substantially as described.

4. The combination, with the shaft A, of the sleeves B, secured thereon,and provided with the pins 1), projecting at right angles to the shaft,the pins on one sleeve lying in a plane at right angles with that of thepins on the other sleeve, a shifter 0, located between the sleeves andhaving two arms 0, extending along the sleeves midway between the pins band the disks D, mounted on said pins Z1, and connected with the arms 0,the plane of each disk being at an angle with the axis of the pins,substantially as described.

5. The combination, with the shifter O, of a lever having one endengaging with the shifter and adapted to move it, and a grooved sectorplaced obliquely on a tumbling'shaft and engaging with the other end ofthe lever, substantially as described.

6. The combination, with the shifter O, of the lever I-I, engagingtherewith at one end and carrying at its other end a pivoted block I,having inclined sides, a tumbling-shaft L, a sector K, secured theretoin an oblique position and having a grooved periphery in which the blockI is fitted to slide, substantially as described.

7. The combination, with the flanged shifter C, of the elliptical ringN,fitting between the flanges and provided with pivot-pins n, and a forkedlever engaging with said pins, sub stantially as described.

8. The combination, with a cylindrical flanged shifter C, of anelliptical ri'ng N, fitted between the flanges thereof, having its majoraxis horizontal and its minor axis substantially the same as thediameter of the shifter and provided with pivot-pins n 011 the line ofits minor axis, and a lever having a forked end receiving thepivot-pins,the spread of the fork being somewhat greater than the outer diameter ofthe ring at its minor axis, substantiallyas described.

9. In a valve-gear, the combination, with a grooved disk, of a strapfitted in said groove and composed of two halves united by a belt at oneend and a wedge at the other, whereby the strap can be adj usted forwear, substantially as described.

10. The combination, with the rocking disk D, of the strap E, providedwith the pins 6 and faced off adjacent thereto, and the stirrup F,having the pivot-shaft f, and slotted ends engaging with the pins 6-,substantially as de scribed.

11. The combination, with the locomotiveframes P, of a transverse braceO, the rockarms f, journaled in said brace, the rocking levers Q,mounted on the frames, the adj ustable rods R, uniting the arms f andthe levers Q, and valve-stems S, connected with the rocking levers,substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

I RICHARD GRIFFITH VERE MY'ITON.

Witnesses;

I. G. TOMLINSON, \V. H. TOMLINSON.

